OVERCURRENT PROTECTIVE DEVICE Russian patent published in 2002 - IPC

FIELD: overcurrent protection of communication centers. SUBSTANCE: protective device that functions to protect telephone exchanges against ingress of abnormal load currents through subscribers' conductors has insulating case with input and output contacts, at least one positive-coefficient thermistor with at least one of its leads soldered to input or output terminal of device using solder whose melting point is higher than reference temperature of thermistor but lower than temperature initiating device case destruction. Heat-resistant spring is placed in compressed state between thermistor leads and electrically insulated from at least one of them. Novelty is introduction of additional cutoff stage. EFFECT: enhanced efficiency and reliability of device. 2 cl, 2 dwg